Varied pore organization in mesostructured semiconductors based on the [SnSe4] (4-) anion

Open framework metal chalcogenide solids, with pore sizes in the nano- and mesoscale, are of potentially broad technological and fundamental interest in research areas ranging from optoelectronics to the physics of quantum co nfinement(1,2). Although there have been significant advances in the design and synthesis of mesostructured silicas(3,4), the construction of their no n-oxidic analogues still remains a challenge. Here we describe a synthetic strategy that allows the preparation of a large class of mesoporous materia ls based on supramolecular assembly of tetrahedral Zintl anions [SnSe4](4-) with transition metals in the presence of cetylpyridinium (CP) surfactant molecules. These mesostructured semiconducting selenide materials are of th e general formulae (CP)(4-2x)MxSnSe4 (where 1.0 < x < 1.3; M = Mn, Fe, Co, Zn, Cd, Hg). The resulting materials are open framework chalcogenides and f orm mesophases with uniform pore size (with spacings between 35 and 40 Angs trom). The pore arrangement depends on the synthetic conditions and metal u sed, and include disordered wormhole, hexagonal and even cubic phases. All compounds are medium bandgap semiconductors (varying between 1.4 and 2.5 eV ). We expect that such semiconducting porous networks could be used for opt oelectronic, photosynthetic and photocatalytic applications.